Hi Henning,
On Wed, Sep 10, 2014 at 1:45 AM, Henning Rogge <hrogge@xxxxxxxxx> wrote:
> Hi,
>
> I am curious, what is the use case for this API? Is there really
> 802.11 hardware that tracks its physical motion?
I was thinking this might be useful for something like a combined WiFi
+ Bluetooth + cellular + GPS chipset in a tablet or laptop.
Thanks,
Julian Calaby
> Henning Rogge
>
> On Tue, Sep 9, 2014 at 3:07 PM, Emmanuel Grumbach
> <emmanuel.grumbach@xxxxxxxxx> wrote:
>> From: Avraham Stern <avraham.stern@xxxxxxxxx>
>>
>> Add API to notify user-space when the device is in motion
>> and the motion type.
>> This information can be used to react to the changing environment when
>> the device is on the move, or avoid some unnecessary activities when
>> the device is not moving. For example, longer scan intervals when the
>> device is not moving and there are probably no new AP's, shorter scan
>> intervals while the device is moving slowly and the environment is
>> constantly changing, and not scanning at all when the device is moving
>> fast and it is very unlikely to be able to connect to anything.
>>
>> Signed-off-by: Avraham Stern <avraham.stern@xxxxxxxxx>
>> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
>> ---
>> include/net/cfg80211.h | 14 ++++++++
>> include/uapi/linux/nl80211.h | 39 ++++++++++++++++++++++
>> net/wireless/core.h | 2 ++
>> net/wireless/nl80211.c | 78 ++++++++++++++++++++++++++++++++++++++++++++
>> net/wireless/trace.h | 14 ++++++++
>> 5 files changed, 147 insertions(+)
>>
>> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
>> index b960c4d..6210822 100644
>> --- a/include/net/cfg80211.h
>> +++ b/include/net/cfg80211.h
>> @@ -4914,6 +4914,20 @@ void cfg80211_shutdown_all_interfaces(struct wiphy *wiphy);
>> /* ethtool helper */
>> void cfg80211_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info);
>>
>> +/*
>> + * cfg80211_device_motion_notify - notify device motion type
>> + *
>> + * @wiphy: the wiphy
>> + * @type: the motion type as specified in &enum nl80211_device_motion_type.
>> + * @gfp: allocation flags
>> + *
>> + * This function is used to report to userspace the type of motion the device
>> + * is currently in.
>> + */
>> +void cfg80211_device_motion_notify(struct wiphy *wiphy,
>> + enum nl80211_device_motion_type type,
>> + gfp_t gfp);
>> +
>> /* Logging, debugging and troubleshooting/diagnostic helpers. */
>>
>> /* wiphy_printk helpers, similar to dev_printk */
>> diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
>> index 8270024..fae01c7 100644
>> --- a/include/uapi/linux/nl80211.h
>> +++ b/include/uapi/linux/nl80211.h
>> @@ -733,6 +733,19 @@
>> * QoS mapping is relevant for IP packets, it is only valid during an
>> * association. This is cleared on disassociation and AP restart.
>> *
>> + * @NL80211_CMD_DEVICE_MOTION_NOTIFY: Device motion notification. This command
>> + * is used as an event to indicate the motion type the device is currently
>> + * in. This command can also be used by userspace to get the current
>> + * motion type. The motion type is specified by the
>> + * %NL80211_ATTR_DEVICE_MOTION_TYPE. This information can be used to react
>> + * to the changing environment when the device is on the move, or avoid
>> + * some unnecessary activities when the device is not moving. For example,
>> + * longer scan intervals when the device is not moving and neighbor AP's
>> + * probably stay the same, shorter scan intervals while the device is
>> + * moving slowly and the environment is changing constantly, and not
>> + * scanning at all when the device is moving fast and it is very unlikely
>> + * to be able to connect to anything.
>> + *
>> * @NL80211_CMD_MAX: highest used command number
>> * @__NL80211_CMD_AFTER_LAST: internal use
>> */
>> @@ -906,6 +919,8 @@ enum nl80211_commands {
>>
>> NL80211_CMD_CH_SWITCH_STARTED_NOTIFY,
>>
>> + NL80211_CMD_DEVICE_MOTION_NOTIFY,
>> +
>> /* add new commands above here */
>>
>> /* used to define NL80211_CMD_MAX below */
>> @@ -1620,6 +1635,9 @@ enum nl80211_commands {
>> * association request. In addition, it must also set the RRM capability
>> * flag in the association request's Capability Info field.
>> *
>> + * @NL80211_ATTR_DEVICE_MOTION_TYPE: The type of motion the device is currently
>> + * in. As specified in &enum nl80211_device_motion_type.
>> + *
>> * @NL80211_ATTR_MAX: highest attribute number currently defined
>> * @__NL80211_ATTR_AFTER_LAST: internal use
>> */
>> @@ -1964,6 +1982,8 @@ enum nl80211_attrs {
>>
>> NL80211_ATTR_USE_RRM,
>>
>> + NL80211_ATTR_DEVICE_MOTION_TYPE,
>> +
>> /* add attributes here, update the policy in nl80211.c */
>>
>> __NL80211_ATTR_AFTER_LAST,
>> @@ -4223,4 +4243,23 @@ enum nl80211_tdls_peer_capability {
>> NL80211_TDLS_PEER_WMM = 1<<2,
>> };
>>
>> +/**
>> + * enum nl80211_device_motion_type - device motion types
>> + * @NL80211_DEVICE_MOTION_TYPE_UNKNOWN: The device motion type is not known
>> + * or has not been set yet.
>> + * @NL80211_DEVICE_MOTION_TYPE_NOT_MOVING: The device is not moving. This
>> + * includes cases in which the device is moving but its immediate
>> + * environment is moving as well, e.g. while on board a train.
>> + * @NL80211_DEVICE_MOTION_TYPE_MOVING_SLOWLY: The device is moving slowly enough
>> + * to keep track of the changing environment.
>> + * @NL80211_DEVICE_MOTION_TYPE_MOVING_FAST: The device is moving fast which
>> + * makes it hard to keep track of the changing environment.
>> + */
>> +enum nl80211_device_motion_type {
>> + NL80211_DEVICE_MOTION_TYPE_UNKNOWN,
>> + NL80211_DEVICE_MOTION_TYPE_NOT_MOVING,
>> + NL80211_DEVICE_MOTION_TYPE_MOVING_SLOWLY,
>> + NL80211_DEVICE_MOTION_TYPE_MOVING_FAST,
>> +};
>> +
>> #endif /* __LINUX_NL80211_H */
>> diff --git a/net/wireless/core.h b/net/wireless/core.h
>> index 21d4b1d..a00be85 100644
>> --- a/net/wireless/core.h
>> +++ b/net/wireless/core.h
>> @@ -84,6 +84,8 @@ struct cfg80211_registered_device {
>> struct list_head destroy_list;
>> struct work_struct destroy_work;
>>
>> + enum nl80211_device_motion_type motion_type;
>> +
>> /* must be last because of the way we do wiphy_priv(),
>> * and it should at least be aligned to NETDEV_ALIGN */
>> struct wiphy wiphy __aligned(NETDEV_ALIGN);
>> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
>> index 03b5b5e..c7c014c 100644
>> --- a/net/wireless/nl80211.c
>> +++ b/net/wireless/nl80211.c
>> @@ -9451,6 +9451,48 @@ static int nl80211_set_qos_map(struct sk_buff *skb,
>> return ret;
>> }
>>
>> +static int nl80211_send_motion(struct sk_buff *msg, u32 portid, u32 seq,
>> + int flags,
>> + struct cfg80211_registered_device *rdev)
>> +{
>> + void *hdr;
>> +
>> + hdr = nl80211hdr_put(msg, portid, seq, flags,
>> + NL80211_CMD_DEVICE_MOTION_NOTIFY);
>> + if (!hdr)
>> + return -ENOBUFS;
>> +
>> + if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||
>> + nla_put_u32(msg, NL80211_ATTR_DEVICE_MOTION_TYPE,
>> + rdev->motion_type))
>> + goto nla_put_failure;
>> +
>> + return genlmsg_end(msg, hdr);
>> +
>> + nla_put_failure:
>> + genlmsg_cancel(msg, hdr);
>> + return -ENOBUFS;
>> +}
>> +
>> +static int nl80211_device_motion_notify(struct sk_buff *skb,
>> + struct genl_info *info)
>> +{
>> + struct sk_buff *msg;
>> + struct cfg80211_registered_device *rdev = info->user_ptr[0];
>> +
>> + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
>> + if (!msg)
>> + return -ENOMEM;
>> +
>> + if (nl80211_send_motion(msg, genl_info_snd_portid(info), info->snd_seq,
>> + 0, rdev) < 0) {
>> + nlmsg_free(msg);
>> + return -ENOBUFS;
>> + }
>> +
>> + return genlmsg_reply(msg, info);
>> +}
>> +
>> #define NL80211_FLAG_NEED_WIPHY 0x01
>> #define NL80211_FLAG_NEED_NETDEV 0x02
>> #define NL80211_FLAG_NEED_RTNL 0x04
>> @@ -10197,6 +10239,14 @@ static __genl_const struct genl_ops nl80211_ops[] = {
>> .internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
>> NL80211_FLAG_NEED_RTNL,
>> },
>> + {
>> + .cmd = NL80211_CMD_DEVICE_MOTION_NOTIFY,
>> + .doit = nl80211_device_motion_notify,
>> + .policy = nl80211_policy,
>> + .flags = GENL_ADMIN_PERM,
>> + .internal_flags = NL80211_FLAG_NEED_WIPHY |
>> + NL80211_FLAG_NEED_RTNL,
>> + },
>> };
>>
>> /* notification functions */
>> @@ -12004,6 +12054,34 @@ void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp)
>> }
>> EXPORT_SYMBOL(cfg80211_crit_proto_stopped);
>>
>> +void cfg80211_device_motion_notify(struct wiphy *wiphy,
>> + enum nl80211_device_motion_type type,
>> + gfp_t gfp)
>> +{
>> + struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
>> + struct sk_buff *msg;
>> +
>> + trace_cfg80211_device_motion_notify(wiphy, type);
>> +
>> + if (rdev->motion_type == type)
>> + return;
>> +
>> + rdev->motion_type = type;
>> +
>> + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
>> + if (!msg)
>> + return;
>> +
>> + if (nl80211_send_motion(msg, 0, 0, 0, rdev) < 0) {
>> + nlmsg_free(msg);
>> + return;
>> + }
>> +
>> + genlmsg_multicast_netns(&nl80211_fam, wiphy_net(wiphy), msg, 0,
>> + NL80211_MCGRP_SCAN, gfp);
>> +}
>> +EXPORT_SYMBOL(cfg80211_device_motion_notify);
>> +
>> void nl80211_send_ap_stopped(struct wireless_dev *wdev)
>> {
>> struct wiphy *wiphy = wdev->wiphy;
>> diff --git a/net/wireless/trace.h b/net/wireless/trace.h
>> index 0f0901e..e39a950 100644
>> --- a/net/wireless/trace.h
>> +++ b/net/wireless/trace.h
>> @@ -2627,6 +2627,20 @@ TRACE_EVENT(cfg80211_stop_iface,
>> WIPHY_PR_ARG, WDEV_PR_ARG)
>> );
>>
>> +TRACE_EVENT(cfg80211_device_motion_notify,
>> + TP_PROTO(struct wiphy *wiphy, enum nl80211_device_motion_type type),
>> + TP_ARGS(wiphy, type),
>> + TP_STRUCT__entry(
>> + WIPHY_ENTRY
>> + __field(enum nl80211_device_motion_type, type)
>> + ),
>> + TP_fast_assign(
>> + WIPHY_ASSIGN;
>> + __entry->type = type;
>> + ),
>> + TP_printk(WIPHY_PR_FMT ", type: %d", WIPHY_PR_ARG, __entry->type)
>> +);
>> +
>> #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
>>
>> #undef TRACE_INCLUDE_PATH
>> --
>> 1.9.1
>>
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--
Julian Calaby
Email: julian.calaby@xxxxxxxxx
Profile: http://www.google.com/profiles/julian.calaby/
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